SYNTHESIS OF MAGNESIUM-POLYLACTIC HYBRID BIOMATERIAL FOR BONE REGENERATION. CHARACTERIZATION AND BIODEGRADATION EVALUATION

Abstract

Critical-Size Defects (CSD) represent a great challenge in orthopedic and reconstructive surgery, requiring innovative materials to address their complexity and limitations of current prosthetic solutions. Traditional biomaterials, including natural biodegradable polymers, bioceramics, and metals such as titanium, Mg, and Zn, provide benefits. However, they often do not achieve meeting the optimal balance of mechanical properties, biocompatibility, and controlled degradation. Hybrid biomaterials are emerging as promising alternatives, combining the strengths of different materials to meet these requirements. This project explores the development of a new hybrid biomaterial composed of Mg alloy AZ91 and Poly-Lactic Acid (PLA) to treat CSD. The AZ91 plates were fabricated using Laser Powder Bed Fusion (LPBF), a cutting-edge additive manufacturing technique offering precise control over structural and material properties. The integration of these metallic components with PLA matrices was achieved through a systematic trial-and- error process, refining temperature and pressure parameters to ensure homogeneity and structural cohesion. Unlike traditional coating-based approaches, this hybrid structure eliminates delamination risks. The study further evaluates the hybrid material¿s properties through an extensive biodegradability assessment, focusing on electrochemical corrosion under physiological conditions. Key experiments, including hydrogen release studies, pH monitoring, and mass loss analysis, were conducted to characterize degradation dynamics. These tests reveal how the hybrid material addresses common issues, such as rapid degradation of Mg and limited biocompatibility of polymers, by combining their complementary properties. The resulting material exhibits controlled biodegradation, improved mechanical strength, and enhanced biocompatibility, making it a compelling candidate for temporary implants that gradually integrate into surrounding bone tissue without the need for removal surgery. The findings of this research contribute to advancing the field of hybrid biomaterials for bone regeneration, offering a sustainable and innovative solution for patients suffering from severe bone defects. This study sets the foundation for future biomedical applications, including tailored implants that prioritize patient safety, effectiveness, and customization.